CN113593477A

CN113593477A - Display device and driving method thereof

Info

Publication number: CN113593477A
Application number: CN202110883756.5A
Authority: CN
Inventors: 窦维
Original assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2021-08-03
Filing date: 2021-08-03
Publication date: 2021-11-02

Abstract

The application discloses a display device and a driving method thereof. The driving method includes: acquiring a pre-prediction characteristic value for controlling a pixel; judging whether the pre-prediction characteristic value is in a specific interval or not; when the pre-characteristic value is in the specific interval, calculating an attenuation coefficient, and calculating a target characteristic value according to the attenuation coefficient, wherein the attenuation coefficient and a numerical value in the specific interval are in a linear relation; and controlling the luminous intensity of the pixel according to the target characteristic value. The target characteristic value is calculated according to the attenuation coefficient, wherein the attenuation coefficient is in a linear relation with the numerical value in the specific interval. The display device controls the luminous intensity of the pixels based on the target characteristic value, so that the phenomenon of gray scale or brightness inversion of the picture can be avoided.

Description

Display device and driving method thereof

Technical Field

The present disclosure relates to display technologies, and particularly to a display device and a driving method thereof.

Background

With the development of display technologies, the variety of display products is gradually diversified. In the research of display products, how to improve the display effect and reduce the power consumption is a topic of great concern.

Organic light-emitting diode (OLED) displays and light-emitting diode (LED) displays have the characteristic of self-luminescence, so that the luminous intensity of each pixel can be controlled independently. The luminous intensity of a pixel is closely related to the display power consumption. For large-size OLED or LED displays, large-area light can be emitted during display, so that the large-area OLED or LED display can be used as a large-area surface light source. According to the research of the field of vision of human eyes, when human eyes watch a surface light source with uniform light intensity, the perception capability of the human eyes to the light intensity is gradually weakened from the center of the light source to the periphery. Therefore, the power consumption of the large-sized OLED or LED display can be further reduced by the characteristic.

In the art of reducing power consumption, a Convex Power Control (CPC) algorithm has been proposed. The CPC algorithm is an algorithm for controlling power consumption of a display device by reducing brightness of a partial area. Specifically, the preset luminance value of the partial region is multiplied by a fixed value of the attenuation coefficient to reduce the luminance value of the actual output, wherein the farther the region is from the center of the screen, the larger the attenuation coefficient is. However, according to the conventional setting scheme of the attenuation coefficient, when some special images are displayed, gray scales or brightness inversion occurs, which results in a reduction of the display effect.

Referring to fig. 1A and 1B, fig. 1A is a schematic diagram illustrating an attenuation coefficient setting scheme of CPC calculation in the prior art, and fig. 1B is a schematic diagram illustrating an input gray-scale value and an output gray-scale value calculated by using the CPC of fig. 1A in the prior art. As shown in fig. 1A, after determining the attenuation coefficient according to the distance between the display area and the center of the screen, not all the input gray-scale values or luminance values are multiplied by the attenuation coefficient, but when the input gray-scale values or luminance values are greater than the set threshold gray-scale values or threshold luminance values, the input gray-scale values or luminance values are attenuated by using the attenuation coefficient of a fixed value. When the input gray scale value or luminance value is lower than the set threshold gray scale value or threshold luminance value, too much detail of the low luminance is lost in order to avoid influence, i.e., attenuation is not performed. As shown in fig. 1B, taking the gray scale values as an example, the input gray scale values range from 0 to 255 gray scales. Line a is the line of the relationship between the input gray-scale value and the output gray-scale value calculated without using the CPC, and line B is the line of the relationship between the input gray-scale value and the output gray-scale value calculated using the CPC attenuation coefficient setting scheme of fig. 1A. Taking a gray scale value with a gray scale of 99 as an example of the threshold gray scale value, the gray scale values above the gray scale of 99 are calculated by using a CPC, and the input gray scale value is multiplied by an attenuation coefficient of a fixed value to obtain a converted output gray scale value. Taking the attenuation coefficient as 20%, when the input gray scale value is 100, the calculated output gray scale value is 80. It can be seen that the output gray scale value obtained when the input gray scale value is 100 is lower than the output gray scale value obtained when the input gray scale value is 99, and thus the output gray scale value is inverted. And, the output gray level obtained when the input gray level is greater than 124 is greater than the output gray level obtained when the input gray level is 99. Therefore, if the relationship curve between the input gray-scale value and the output gray-scale value in fig. 1B is used to control the luminance of the pixel, the pixel should originally display higher luminance relative to another pixel, but the actual output luminance of the pixel calculated by the CPC attenuation coefficient setting scheme in the prior art is relatively lower than the luminance of another pixel.

In view of the above, it is desirable to provide a display device and a driving method thereof to solve the problems in the prior art.

Disclosure of Invention

In order to solve the above-mentioned problems of the prior art, an object of the present application is to provide a display device and a driving method thereof, which can reduce power consumption of the display device and avoid gray scales or brightness inversion of a display screen.

To achieve the above objective, the present application provides a driving method of a display device. The driving method includes:

acquiring a preset characteristic value for controlling a pixel;

judging whether the preset characteristic value is in a specific interval or not;

when the preset characteristic value is in the specific interval, calculating an attenuation coefficient, and calculating a target characteristic value according to the attenuation coefficient, wherein the attenuation coefficient and a numerical value in the specific interval are in a linear relation; and

and controlling the luminous intensity of the pixel according to the target characteristic value.

In some embodiments, the target feature value is greater than or equal to another target feature value obtained by calculating another preset feature value lower than the preset feature value by 1.

In some embodiments, the attenuation coefficient is formulated as:

wherein K is the attenuation coefficient, E_inTo the preset characteristic value, E_MinIs the minimum value of the specified interval, E_MaxIs the maximum value of said specific interval, K_MaxIs the maximum attenuation coefficient.

In some embodiments, the maximum attenuation coefficient is formulated as:

in some embodiments, after determining whether the preset feature value is in a specific interval, the method further includes: when the preset characteristic value is smaller than the minimum value of the specific interval, the attenuation coefficient is 0, and the target characteristic value is equal to the preset characteristic value.

In some embodiments, after determining whether the preset feature value is in a specific interval, the method further includes: when the preset characteristic value is larger than the maximum value of the specific interval, calculating a target characteristic value according to a maximum attenuation coefficient, wherein the formula of the maximum attenuation coefficient is as follows:

wherein K_MaxTo maximum attenuation coefficient, E_MaxIs the maximum value of said specific interval, E_MinIs the minimum value of the specific interval.

The application also provides a display device. The display device comprises a time schedule controller, a grid controller, a source electrode controller and a display panel.

The time schedule controller is used for storing a plurality of preset characteristic values configured to control a plurality of pixels, calculating an attenuation coefficient when the preset characteristic values are judged to be in a specific interval, and calculating a target characteristic value according to the attenuation coefficient, wherein the attenuation coefficient and the numerical value in the specific interval are in a linear relation.

The gate controller is connected with the timing controller and configured to output a gate signal.

The source controller is connected with the time sequence controller, and is configured to receive the target characteristic value and convert the target characteristic value into a data voltage.

The display panel is connected with the grid controller and the source controller and is configured to control the luminous intensity of the corresponding pixel based on the data voltage when the grid signal is input.

In some embodiments, the timing controller includes a memory, a comparator, and a calculator.

The memory is configured to store the plurality of preset feature values.

The comparator is connected with the memory and configured to obtain at least one preset characteristic value and compare the preset characteristic value with the end value of the specific interval.

The calculator is connected with the memory and configured to calculate the attenuation coefficient according to the comparison result of the comparator and calculate a target characteristic value according to the attenuation coefficient, wherein the formula of the attenuation coefficient is as follows:

In some embodiments, in response to the comparison result of the comparator being that the preset feature value is smaller than the minimum value of the specific interval, the attenuation coefficient is 0, and the target feature value is equal to the preset feature value.

In some embodiments, in response to the comparison result of the comparator being that the preset characteristic value is greater than the maximum value of the specific interval, the calculator calculates a maximum attenuation coefficient, and calculates a target characteristic value according to the maximum attenuation coefficient, wherein the maximum attenuation coefficient is expressed by:

Compared with the prior art, the method and the device have the advantages that when the preset characteristic value of the pixel is in the specific interval, the attenuation coefficient which is in a linear relation with the value in the specific interval is calculated, and the target characteristic value is calculated according to the attenuation coefficient. The display device controls the light emission intensity of the corresponding pixel based on the target characteristic value. Through the CPC calculation of the application, the phenomenon of gray scale or brightness inversion of the picture can be avoided, and the reduction of the display effect is further avoided.

Drawings

The technical solution and other advantages of the present application will become apparent from the detailed description of the embodiments of the present application with reference to the accompanying drawings.

Fig. 1A shows a schematic diagram of an attenuation coefficient setting scheme for CPC calculation in the prior art.

FIG. 1B is a diagram illustrating input and output gray-scale values calculated using the CPC of FIG. 1A according to the prior art.

Fig. 2 shows a schematic diagram of a display device according to an embodiment of the present application.

Fig. 3 shows a flowchart of a driving method of a display device according to an embodiment of the present application.

Fig. 4 shows a diagram of the relationship between the preset characteristic value and the attenuation coefficient of the present application.

Fig. 5 is a schematic diagram showing the preset characteristic value and the target characteristic value obtained according to the attenuation coefficient.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 2, a schematic diagram of a display device 10 according to an embodiment of the present application is shown. The display device 10 includes a timing controller 110, a source controller 120, a gate controller 130, and a display panel 140. The timing controller 110 is connected to the source controller 120 and the gate controller 130. The source controller 120 is connected to the display panel 140 through a plurality of data lines. The gate controller 130 is connected to the display panel 140 through a plurality of gate lines. The display panel 140 includes a plurality of pixels P, each of which is connected to a corresponding data line and gate line.

As shown in fig. 2, the timing controller 110 includes a memory 111, a comparator 112, and a calculator 113. The timing controller 110 acquires a plurality of preset feature values regarding a plurality of pixels displaying one frame of a picture, and stores the preset feature values in the memory 111. In the present embodiment, the timing controller 110 performs a Convex Power Control (CPC) calculation using the memory 111, the comparator 112, and the calculator 113 to convert a preset feature value into a target feature value. The CPC calculation performed by the timing controller 110 will be described in detail later.

The gate controller 130 outputs a corresponding gate signal based on the timing signal from the timing controller 110 and applies the gate signal to the display panel 140 to control the switching elements of the pixels P to be turned on or off.

The source controller 120 is configured to receive the target characteristic value from the timing controller 110 and convert the target characteristic value into a data voltage. The source controller 120 inputs the data voltage to the display panel 140 so that the display panel 140 controls the light emission intensity of the corresponding pixel based on the data voltage obtained according to the target characteristic value.

In the present application, the CPC calculation performed by the timing controller 110 can implement an algorithm that reduces the brightness of the screen to control the power consumption of the display without affecting the visual effect. In addition, through CPC calculation of this application can avoid appearing the grey scale or the luminance reversal phenomenon when showing some special picture, and then avoids the display effect to descend. The specific steps of the CPC calculation performed by the timing controller 110 are as follows. It should be noted that the timing controller 110 performs CPC calculation only for a partial area of the display panel, such as a surrounding area of the display panel, to reduce the luminance of the partial area to achieve control of power consumption of the display device.

Referring to fig. 2 and 3, fig. 3 shows a flowchart of a driving method of the display device 10 according to an embodiment of the present application.

In step S101, the timing controller 110 acquires a plurality of preset feature values with respect to a plurality of pixels displaying one frame of a picture. It should be noted that the characteristic value of the present application is a parameter value for controlling the light emission intensity of the pixel, including a gray-scale value and/or a luminance value of the pixel. For example, when the feature value is a gray scale value, the preset feature value is a value ranging from 0 to 255 gray scales.

In step S102, the timing controller 110 determines whether the preset feature value is in a specific interval. Specifically, the timing controller 110 compares the preset characteristic value with the end value of the specific interval through the comparator 112 to determine whether the preset characteristic value is in the specific interval. The logic for selecting the value of the specific interval is to perform no additional calculation to reduce the brightness when the predetermined characteristic value is smaller than the specific interval. When the predetermined characteristic value is within the specific interval, the attenuation coefficient for performing the CPC calculation increases as the characteristic value increases, and the attenuation coefficient is in a linear relationship with the value within the specific interval. The CPC calculation is performed using the maximum attenuation coefficient when the preset eigenvalue is greater than the specific interval. The CPC calculation of the application can reduce the power consumption by reducing the luminous intensity of the pixel, and simultaneously ensures the display quality of the picture. It should be understood that the values of the specific intervals of the present application can be customized by the manufacturer according to different product characteristics. For example, for a certain product a, the light emitting efficiency and optical characteristics thereof require that a precise gray scale value must be used to ensure the display quality at low luminance, and therefore, the minimum value of the specific interval should be set to a relatively large value. In addition, since the product B, which requires relatively high power consumption, requires relatively low accuracy in displaying low luminance, the minimum value of the specific section can be set to a relatively small value, thereby increasing the ability to control power consumption. If the minimum value of the specific interval is set too low, uneven brightness (mura) may occur on the screen. If the minimum value of the specific interval is set too high, the effect of reducing power consumption may be poor. Similarly, the logic for setting the maximum value in the specific interval is similar to the logic for setting the minimum value. When the maximum value of the specific section is set lower, the power consumption reduction capability is stronger, but the loss of the display effect is also increased. The loss of display effect should be controlled within an acceptable range of picture quality. Therefore, different products have different setting requirements of the numerical value in the specific interval.

As shown in fig. 3, when the comparison result of the comparator 112 is that the preset feature value is in the specific interval, step S103 is executed. In step S103, the timing controller 110 calculates the attenuation coefficient through the calculator 113. Specifically, the calculator 113 first calculates the maximum attenuation coefficient according to the end value of the specific interval, and then the calculator 113 calculates the attenuation coefficient corresponding to the preset characteristic value according to the maximum attenuation coefficient. The formula for the maximum attenuation coefficient is:

in the formula (1), K_MaxTo maximum attenuation coefficient, E_MaxIs the maximum value of a specific interval, E_MinIs the minimum value of the specified interval. The maximum attenuation coefficient in the CPC calculation can be determined by equation (1).

The formula of the attenuation coefficient is:

in the formula (2), K is an attenuation coefficient, E_inIs a preset characteristic value. Referring to fig. 4, a graph of the preset characteristic value versus attenuation coefficient of the present application is shown. As shown in FIG. 4, in a specific interval, the attenuation coefficient is within the specific intervalThe values of (A) are linear. It will be appreciated that the same maximum attenuation coefficient is selected for the same area of the panel and that different maximum attenuation coefficients are selected for different areas of the panel. The maximum attenuation coefficient increases from the center of the panel to the edge. The maximum attenuation coefficient must conform to equation (1) regardless of which region of the panel the CPC calculation is performed.

In the present application, the maximum attenuation coefficient means the maximum value of the attenuation coefficient that can be set without gray scale or luminance inversion. Since the maximum attenuation coefficient and the end value of the specific section are in a correlation, the maximum attenuation coefficient can be calculated from the set specific section. In some embodiments, the maximum attenuation factor that needs to be set for the power consumption reduction target to be achieved may also be considered, and a reasonable specific interval is calculated according to equation (2).

As shown in fig. 3, when the calculator 113 calculates the attenuation coefficient, step S104 is performed. In step S104, the calculator 113 calculates a target feature value according to the attenuation coefficient, wherein the target feature value is calculated by the following formula:

E_out＝E_in*(1–K) (3)

in the formula (3), E_outIs the target characteristic value.

As can be seen from equation (3), the magnitude of the attenuation coefficient affects the control capability of the CPC algorithm on power consumption. When the value of the attenuation coefficient is larger, the calculated target characteristic value is lower, the light emitting luminance of the pixel is attenuated more, and therefore the power consumption of the display device is lower. The attenuation coefficient is in the range of 0-1.

In the present application, the derivation formula of formula (1) of the maximum attenuation coefficient is:

in the formula (4), (E)_in-1) is another preset feature value that is 1 unit lower than the preset feature value of the current pixel (e.g., a gray scale value that is 1 gray scale lower). Therefore, the target characteristic value obtained by the calculation is greater than or equal to another value 1 unit lower than the preset characteristic value by the calculationA preset characteristic value and another target characteristic value. It should be understood that there are two kinds of brightness inversion phenomena, including: the brightness of the same pixel is reversed between two different frames and between two pixels in different areas of the same frame, but for the same reason. The above two brightness inversion situations can be avoided simultaneously by the formula (1) of the maximum attenuation coefficient derived by the formula (4).

As shown in fig. 3, when the calculator 113 calculates the target feature value, step S105 is performed. In step S105, the light emission intensity of the pixel is controlled according to the target feature value. Specifically, the gate controller 130 outputs a corresponding gate signal based on the clock signal from the timing controller 110 and applies the gate signal to the display panel 140 to control the switching elements of the pixels P to be turned on or off. The source controller 120 receives the target characteristic value from the timing controller 110 and converts the target characteristic value into a data voltage. The source controller 120 inputs the data voltage to the display panel 140 so that the display panel 140 controls the light emission intensity of the corresponding pixel based on the data voltage obtained according to the target characteristic value.

When the maximum attenuation coefficient and the end value of the specific interval satisfy the formula (1), the problem of gray scale or brightness inversion of the display image can be thoroughly solved. Referring to fig. 5, a schematic diagram of the preset characteristic value and the target characteristic value obtained according to the attenuation coefficient is shown. In fig. 5, taking as an example the calculation of a reasonable maximum attenuation coefficient from a certain interval: the eigenvalues are assumed to be gray-scale values and the specific interval is 80 to 160. That is, the minimum value of the specific interval is 80, and the maximum value E of the specific interval _Max160. The maximum attenuation coefficient K calculated by the formula (1)_MaxLess than or equal to 33.47 percent. As shown in fig. 4, when the maximum attenuation coefficient is set to K_MaxWhen the gray scale value is less than or equal to 33.47%, the preset characteristic value is attenuated by the CPC algorithm in a specific interval of 80-160%, and the inversion phenomenon cannot occur. E_Max＝160

On the other hand, as shown in fig. 3, when the comparison result of the comparator 112 is that the preset feature value is not in the specific section, step S106 is performed. In step S106, it is determined whether the preset feature value is greater than the maximum value of the specific section. Specifically, the timing controller 110 compares the preset characteristic value with the maximum value of the specific interval through the comparator 112 to determine whether the preset characteristic value is greater than the maximum value of the specific interval. When the preset feature value is larger than the maximum value of the specific section, step S107 is performed. When the preset feature value is not greater than the maximum value of the specific section, step S109 is performed.

As shown in fig. 3, in step S107, the maximum attenuation coefficient is calculated. It should be understood that the maximum attenuation coefficient can be calculated by the above equation (1).

As shown in fig. 4, when the preset feature value is larger than the maximum value of the specific section, the maximum attenuation coefficient is used as the attenuation coefficient of the CPC calculation. Therefore, as shown in fig. 3, after the maximum attenuation coefficient is calculated, step S108 is performed. In step S108, the calculator 113 calculates a target feature value according to the maximum attenuation coefficient, where the target feature value is calculated by the following formula: e_out＝E_in*(1–K_Max). As shown in fig. 5, since the present application sets an appropriate value of the specific section, when the preset feature value is larger than the maximum value of the specific section, the maximum attenuation coefficient is used as the attenuation coefficient for CPC calculation, and the obtained target feature value does not have a reversal phenomenon.

As shown in fig. 3, when the calculator 113 calculates the target feature value, step S105 is performed. Step S105 is as described above, and will not be described herein.

Further, as shown in fig. 3, in step S109, when the preset feature value is not greater than the maximum value of the specific section, it is equivalent that the preset feature value is smaller than the minimum value of the specific section. At this time, as shown in fig. 4, when the preset feature value is smaller than the minimum value of the specific section, the attenuation coefficient of CPC calculation is 0. That is, the calculated target characteristic value is equal to the preset characteristic value. Therefore, in some embodiments, when the timing controller 110 determines that the preset feature value is smaller than the specific interval, no additional calculation is performed, and the light emitting intensity of the pixel is controlled according to the preset feature value, i.e., the brightness of the pixel is not reduced. As shown in fig. 5, since the present application sets the appropriate value of the specific interval, when the preset feature value is smaller than the small value of the specific interval, the attenuation coefficient having a value of 0 is used, and the obtained target feature value does not have the inversion phenomenon.

As shown in fig. 3, when the preset feature value is used as the target feature value, step S105 is performed. Step S105 is as described above, and will not be described herein.

In summary, according to the present application, when the preset feature value of the pixel is in the specific interval, the attenuation coefficient which is in a linear relationship with the value in the specific interval is calculated, and the target feature value is calculated according to the attenuation coefficient. The display device controls the light emission intensity of the corresponding pixel based on the target characteristic value. Through the CPC calculation of the application, the phenomenon of gray scale or brightness inversion of the picture can be avoided, and the reduction of the display effect is further avoided.

A display device and a driving method thereof provided in the embodiments of the present application are described in detail above. The principles and implementations of the present application are described herein using specific examples. The above description of the embodiments is only for assisting understanding of the technical solutions of the present application and the core ideas thereof. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Such modifications or substitutions do not depart from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. A driving method of a display device, the driving method comprising:

acquiring a preset characteristic value for controlling a pixel;

2. The method of driving a display device according to claim 1, wherein the target characteristic value is greater than or equal to another target characteristic value obtained by calculating another preset characteristic value lower than the preset characteristic value by 1.

3. The driving method of a display device according to claim 1, wherein the attenuation coefficient is expressed by the formula:

4. A driving method of a display device according to claim 3, wherein the maximum attenuation coefficient is expressed by the formula:

5. the method for driving a display device according to claim 1, further comprising, after determining whether the preset feature value is in a specific interval:

when the preset characteristic value is smaller than the minimum value of the specific interval, the attenuation coefficient is 0, and the target characteristic value is equal to the preset characteristic value.

6. The method for driving a display device according to claim 1, further comprising, after determining whether the preset feature value is in a specific interval:

when the preset characteristic value is larger than the maximum value of the specific interval, calculating a target characteristic value according to a maximum attenuation coefficient, wherein the formula of the maximum attenuation coefficient is as follows:

7. A display device, characterized in that the display device comprises:

the time sequence controller is used for calculating an attenuation coefficient when judging that the preset characteristic value is in a specific interval, and calculating a target characteristic value according to the attenuation coefficient, wherein the attenuation coefficient and a numerical value in the specific interval are in a linear relation;

a gate controller connected to the timing controller and configured to output a gate signal;

a source controller connected to the timing controller, configured to receive the target characteristic value and convert the target characteristic value into a data voltage; and

and a display panel connected to the gate controller and the source controller and configured to control a light emission intensity of a corresponding pixel based on the data voltage when the gate signal is input.

8. The display device according to claim 7, wherein the timing controller comprises:

a memory configured to store the plurality of preset feature values;

the comparator is connected with the memory and configured to acquire at least one preset characteristic value and compare the preset characteristic value with the end value of the specific interval; and

a calculator connected with the memory and configured to calculate the attenuation coefficient according to the comparison result of the comparator and calculate a target characteristic value according to the attenuation coefficient, wherein the formula of the attenuation coefficient is:

wherein KAs the attenuation coefficient, E_inTo the preset characteristic value, E_MinIs the minimum value of the specified interval, E_MaxIs the maximum value of said specific interval, K_MaxIs the maximum attenuation coefficient.

9. The display device according to claim 8, wherein in response to the comparison result of the comparator being that the preset feature value is smaller than the minimum value of the specific interval, the attenuation coefficient is 0, and the target feature value is equal to the preset feature value.

10. The display device according to claim 8, wherein the calculator calculates a maximum attenuation coefficient in response to the comparison result of the comparator being that the preset characteristic value is greater than a maximum value of the specific section, and calculates a target characteristic value based on the maximum attenuation coefficient, wherein the maximum attenuation coefficient is expressed by: